<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.bootcss.com/jquery/1.11.3/jquery.js"></script>
</head>
<body>

<button type="button" id="test">00:00-06:00</button>

<script>

    $.getJSON('train.json',function (data) {

        //采用filter过滤
        data.result.list = data.result.list.filter(function(item){
            return item.start_time >= "06:42";
        })

        console.log(data);
        alert(data.result.list.length);
    })



</script>
</body>
</html>